With go.Isosurface, you can plot isosurface contours of a scalar field value, which is defined on x, y and z coordinates.

Basic Isosurface¶

In this first example, we plot the isocontours of values isomin=2 and isomax=6. In addition, portions of the sides of the coordinate domains for which the value is between isomin and isomax (named the caps) are colored. Please rotate the figure to visualize both the internal surfaces and the caps surfaces on the sides.

In [1]:

import plotly.graph_objects as go

fig= go.Figure(data=go.Isosurface(
    x=[0,0,0,0,1,1,1,1],
    y=[1,0,1,0,1,0,1,0],
    z=[1,1,0,0,1,1,0,0],
    value=[1,2,3,4,5,6,7,8],
    isomin=2,
    isomax=6,
))

fig.show()

Removing caps when visualizing isosurfaces¶

For a clearer visualization of internal surfaces, it is possible to remove the caps (color-coded surfaces on the sides of the visualization domain). Caps are visible by default.

In [2]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]

# ellipsoid 
values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    isomin=10,
    isomax=40,
    caps=dict(x_show=False, y_show=False)
    ))
fig.show()

Modifying the number of isosurfaces¶

In [3]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]

# ellipsoid 
values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    isomin=10,
    isomax=50,
    surface_count=5, # number of isosurfaces, 2 by default: only min and max
    colorbar_nticks=5, # colorbar ticks correspond to isosurface values
    caps=dict(x_show=False, y_show=False)
    ))
fig.show()

Changing the opacity of isosurfaces¶

In [4]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]

# ellipsoid 
values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    opacity=0.6,
    isomin=10,
    isomax=50,
    surface_count=3,
    caps=dict(x_show=False, y_show=False)
    ))
fig.show()

Isosurface with Addtional Slices¶

Here we visualize slices parallel to the axes on top of isosurfaces. For a clearer visualization, the fill ratio of isosurfaces is decreased below 1 (completely filled).

In [5]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]

# ellipsoid 
values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    isomin=5,
    isomax=50,
    surface_fill=0.4,
    caps=dict(x_show=False, y_show=False),
    slices_z=dict(show=True, locations=[-1, -3,]),
    slices_y=dict(show=True, locations=[0]),
    ))
fig.show()

Multiple Isosurfaces with Caps¶

In [6]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, 0:5:20j]

values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    isomin=30,
    isomax=50,
    surface=dict(count=3, fill=0.7, pattern='odd'),
    caps=dict(x_show=True, y_show=True),
    ))
fig.show()

Changing the default colorscale of isosurfaces¶

In [7]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]

# ellipsoid 
values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    colorscale='BlueRed',
    isomin=10,
    isomax=50,
    surface_count=3,
    caps=dict(x_show=False, y_show=False)
    ))
fig.show()

Customizing the layout and appearance of isosurface plots¶

In [8]:

import plotly.graph_objects as go
import numpy as np

X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, 0:5:20j]

values = X * X * 0.5 + Y * Y + Z * Z * 2

fig = go.Figure(data=go.Isosurface(
    x=X.flatten(),
    y=Y.flatten(),
    z=Z.flatten(),
    value=values.flatten(),
    isomin=30,
    isomax=50,
    surface=dict(count=3, fill=0.7, pattern='odd'),
    showscale=False, # remove colorbar
    caps=dict(x_show=True, y_show=True),
    ))

fig.update_layout(
    margin=dict(t=0, l=0, b=0), # tight layout
    scene_camera_eye=dict(x=1.86, y=0.61, z=0.98))
fig.show()

Reference¶

See https://plot.ly/python/reference/#isosurface for more information and chart attribute options!